1. Field of the Invention
The invention relates generally to spectrometers, and more particularly to a portable apparatus for narrowband radiometry and for real time detection, recording, and display of scientific spectra in the form of radiated and reflected emissions for investigations over the ultraviolet through infrared wavelengths.
2. Description of the Prior Art
High resolution imaging spectrometers are well known to the art. One such spectrometer is disclosed in U.S. Pat. No. 5,149,959, Airborne Multiband Imaging Spectrometer, filed Apr. 15, 1991 and issued to the assignee of the present invention. A spectrometer of this type has proven of great commercial success in surveying for oil spills, mineral deposits, geological formations, vegetation studies, pollution studies, solar spectra, and the like. However, its size and weight make it impractical for field observations, where a lightweight, portable instrument is required.
Further, instruments of this type require complex electro-mechanical systems for control of a scanning mirror and may require the using of Dewars or other cooling techniques to achieve low detector noise levels.
Such portable instruments as have been developed weight up to forty pounds, and may require a backpack for battery and computer support, which mitigates against utility in the field. Where a portable computer has been integrated into the unit, it has required additional interface circuitry to process spectrometric data and control the detector head, adding weight, space, and cost to the system.
The present invention in one embodiment provides a light-weight portable instrument, operative over the 0.3-3.0 .mu.m range, capable of providing raw digital data or operating in radiance, reflectance, irradiance and averaging modes. It features direct coupling to the parallel port of a personal computer for control and readout, hence allowing the use of notebook or laptop type computers for real-time data acquisition and display. Resolutions from 8 to 24 nm over 140 channels are attainable in a compact, lightweight package.